The present invention describes a class of propellants useful as gun or rocket propellants, gas generators, or specialized applications where a very high burning rate is required. The key ingredient of the propellant compositions is a coprecipitate of selected metallic and nonmetallic salts of decahydrodecaboric acid, in combination with certain oxidizing agents. The method of preparing the coprecipitates results in chemical substances in which there is intercrystalline mixing of the substituents, in a chemical state not obtainable by physical blending.
The forementioned coprecipitates replace the oxidizer normally found in typical compositions such as composite propellants, and are responsible for the high burning rates. Other simple decahydrodecaborate salts of selected types, and either soluble or insoluble in the propellant resins or extending solvents, may optionally be additionally used to further enhance the burning rate.
The subject propellants have the general formula as follows:
______________________________________ Probable Range, % by Wt. ______________________________________ 1. Polymeric binder system 8-35 2. Curing, polymerizing, or cross-linking agents 0-10 3. Plasticizing agents 0-25 4. Decahydrodecaborate compounds Class (1) 0-25 5. Decahydrodecaborate compounds Class (2) 35-90 6. Energetic fuels, such as, but not limited to, finely divided aluminum 0-10 7. Oxidizer or mixture of oxidizers to supplement (5) 0-15 8. Other inert ingredients, such as colorants, stabilizers. 0-10 ______________________________________
The ingredients, selected from items (3) through (8) in the above list, are combined in a suitable manner with a binder system selected from items (1) and (2) to form a nonporous propellant with desired physical properties. The key ingredient which distinguishes the subject propellants from other state-of-the-art propellants is the use of decahydrodecaborate compounds (item 5) of class (2), as further defined and described hereinafter. The optional and additional use of decahydrodecaborate compounds of class (1), as defined hereinafter, to enhance burning rate when used with certain "active," that is, oxygen or fluorine containing binders, is also unique.
The two classes of decahydrodecaborate compounds as defined as follows: